Selecting
A Sealing Elastomer

The
selection of a sealing elastomer may seem daunting. By first understanding
the basic chemical alternatives and properties, however, the selection
process is simplified. Knowledge of an elastomer's properties is useful
in predicting seal performance. The proper combination of chemical compatibility,
thermal stability, contamination potential and physical properties will
provide the user with the optimum seal.

The
seal industry uses many tests to determine an elastomer's chemical and
thermal compatibility as well as physical properties which can have
a great influence on the performance in high-pressure or vacuum environments.
These properties can provide an insight into the mode of degradation
or the retention of sealing properties-all useful information in predicting
seal life or comparing economic alternatives.

Another difference in elastomer compounds is
the compounding (or mixing) of ingredients. These factors can provide unique
pigmentation, improved specific chemical or thermal properties, improved dynamic
performance, reduced cost, improved electrical properties, reduced friction
or sticking, and many other aspects of seal performance.